1. Field
The following description relates to an image pickup device, and more particularly, to an image pickup device and a lens module included in the same.
2. Description of the Related Art
Following the development of digital technologies, digital convergence is becoming increasingly popular. Applications of digital convergence are most active in the field of media and communications. A representative digital convergence product is a so-called “camera phone” where an image pickup module such as a digital camera or a digital camcorder is combined with a mobile phone. Image pickup modules such as digital cameras and the like are installed in various mobile electronic devices including laptop computers and Personal Digital Assistants (PDAs) in addition to mobile phones.
As mobile electronic devices with image pickup modules are small and slimline, and are becoming more popular, demands for small, light-weight and low-cost image pickup modules are increasing accordingly. Particularly, in order to keep pace with the recent trend in which various electronic devices, such as MP3 players, Portable Multimedia Players (PMP), Digital Multimedia Broadcasting (DMB) television reception devices, etc., in addition to image pickup modules are integrated into camera phones, the demands for small, low-cost image pickup modules are further increasing.
In order to meet these demands, a wafer-level image pickup module has been developed. A related art lens module (hereinafter, referred to as a wafer-level lens module) for a wafer-level image pickup module has a stacked structure of transparent substrates and polymer lenses. The wafer-level lens module is manufactured by arranging and stacking a plurality of transparent wafers, each having polymer lenses formed in an array using a replica method, and then cutting them. Accordingly, the wafer-level lens module can be manufactured to be small and light-weight at low cost, which allows for mass production.
A related art wafer-level lens, which is manufactured by the replica method, is made of mainly UV curable polymer. In the case of manufacturing a wafer-level lens using UV curable polymer, the manufacturing process is simplified, which leads to a reduction in manufacturing costs. However, there are difficulties in applying such a wafer-level lens module including polymer lenses to 5 Mega pixel or higher resolution cameras. The reason is polymer lenses are easily distorted with respect to shape and exhibit high chromatic aberration.
When camera phones were first introduced, consumer expectations regarding the quality and performance of the camera installed therein were not high. However, recently, as the types of mobile phones have become more varied to satisfy the various demands or tastes of consumers, the demand on resolution of a camera module installed in a camera phone also is becoming higher. In particular, mobile devices with 5 Mega pixel or higher resolution cameras have become widespread, and furthermore such mobile devices are becoming increasingly small and slimline. In order to keep pace with this recent trend, a need for a wafer-level image pickup apparatus that can be used in various applications and supports high performance is increasing.